I'm looking forward to upgrade my flash gear these days, and was wondering if i should get a flash that can be used as a master flash. Not sure if it's going to be Metz 58af2 or Canon 580ex... What I need to know is how does the master wireless flash work. Is it by optical triggering or radio? So let's presume i have a canon 580 ex used as a master and a canon 430ex used as a slave. Both of the flashes allow HSS when used on the camera. So if i have HSS enabled on both flashes and make the rest of the setup, will i still get HHS compatibility with the flashes in wireless mode? Or i can use them only at the sync speed of my camera? Thanks for the responses.